Re: [PATCH 5/6] create internal eofblocks structure with kuid_t types

Brian Foster
2013-06-28T18:12:48Z

On 06/28/2013 11:11 AM, Dwight Engen wrote:
> Have eofblocks ioctl convert uid_t to kuid_t into internal structure.
> Update internal filter matching to compare ids with kuid_t types.
>
> Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
> ---
> fs/xfs/xfs_fs.h | 2 +-
> fs/xfs/xfs_icache.c | 6 +++---
> fs/xfs/xfs_ioctl.c | 34 ++++++++++++++++++++++++++++++++--
> fs/xfs/xfs_linux.h | 8 ++++++++
> 4 files changed, 44 insertions(+), 6 deletions(-)
>
...
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index bedf510..487dca5 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -1328,6 +1328,31 @@ xfs_ioc_getbmapx(
> return 0;
> }
>
> +STATIC int
> +xfs_fs_eofblocks_to_internal(
> + struct xfs_fs_eofblocks *src,
> + struct xfs_eofblocks *dst)
> +{
> + dst->eof_flags = src->eof_flags;
> + dst->eof_prid = src->eof_prid;
> + dst->eof_min_file_size = src->eof_min_file_size;
> +
> + if (src->eof_flags & XFS_EOF_FLAGS_UID) {
> + dst->eof_uid = make_kuid(current_user_ns(), src->eof_uid);
> + if (!uid_valid(dst->eof_uid))
> + return XFS_ERROR(EINVAL);
> + }
> +
> + if (src->eof_flags & XFS_EOF_FLAGS_GID) {
> + dst->eof_gid = make_kgid(current_user_ns(), src->eof_gid);
> + if (!gid_valid(dst->eof_gid))
> + return XFS_ERROR(EINVAL);
> + }
> +
> + return 0;
> +}

Is there any harm in removing the policy from this function, storing a
potentially invalid kuid's in the xfs_eofblocks and letting the caller
determine whether an error should be returned? IOW, this function becomes:

inline void
xfs_fs_eofblocks_to_internal(
struct xfs_fs_eofblocks *src,
struct xfs_eofblocks *dst)
{
dst->eof_flags = src->eof_flags;
dst->eof_prid = src->eof_prid;
dst->eof_min_file_size = src->eof_min_file_size;
dst->eof_uid = make_kuid(current_user_ns(), src->eof_uid);
dst->eof_gid = make_kgid(current_user_ns(), src->eof_gid);
}

... and xfs_file_ioctl() can check the XFS_EOF_FLAGS_UID/GID flags and
validity of the value to determine whether an error should be returned.

Also, I suspect xfs_icache.h might be a better home for this function.

> +
> +
> /*
> * Note: some of the ioctl's return positive numbers as a
> * byte count indicating success, such as readlink_by_handle.
> @@ -1610,7 +1635,8 @@ xfs_file_ioctl(
> return -error;
>
> case XFS_IOC_FREE_EOFBLOCKS: {
> - struct xfs_eofblocks eofb;
> + struct xfs_fs_eofblocks eofb;
> + struct xfs_eofblocks keofb;
>
> if (copy_from_user(&eofb, arg, sizeof(eofb)))
> return -XFS_ERROR(EFAULT);
> @@ -1625,7 +1651,11 @@ xfs_file_ioctl(
> memchr_inv(eofb.pad64, 0, sizeof(eofb.pad64)))
> return -XFS_ERROR(EINVAL);
>
> - error = xfs_icache_free_eofblocks(mp, &eofb);
> + error = xfs_fs_eofblocks_to_internal(&eofb, &keofb);
> + if (error)
> + return -XFS_ERROR(error);
> +
> + error = xfs_icache_free_eofblocks(mp, &keofb);
> return -error;
> }
>
> diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
> index 761e4c0..3c2f403 100644
> --- a/fs/xfs/xfs_linux.h
> +++ b/fs/xfs/xfs_linux.h
> @@ -185,6 +185,14 @@ static inline kgid_t xfs_gid_to_kgid(__uint32_t gid)
> return make_kgid(&init_user_ns, gid);
> }
>
> +struct xfs_eofblocks {
> + __u32 eof_flags;
> + kuid_t eof_uid;
> + kgid_t eof_gid;
> + prid_t eof_prid;
> + __u64 eof_min_file_size;
> +};
> +

xfs_icache.h?

Brian

> /*
> * Various platform dependent calls that don't fit anywhere else
> */